If you disable the manged pages feature, Portal Site library in WCM is no longer automatically synchronized with the portal page structure.

After enabling manged pages feature, you can resynchronize the Portal Site library based on the current portal page structure that is stored in the portal database. If you run this synchronization, the portal database acts a master repository. Any portal page site areas in the Portal Site library that do not correspond with existing portal pages are removed from the Portal Site library. Any content site areas or content items within the affected portal page site areas are also removed.

To perform this resynchronization, run the create-page-nodes configuration task.